Sheet-feeding apparatus

ABSTRACT

The present sheet-feeding apparatus has a plurality of spacedapart transfer belts through which vacuum is applied to the underside of a sheet to enable the transfer belts to move the sheet into a printing press or other machine. A plurality of fingers press the sheet toward the transfer belts to facilitate the application of vacuum to the sheet. In addition, highvelocity jets of air may be directed along the underside of the sheet, alone or in conjunction with the fingers, to form areas of low pressure to enable immediate firm gripping of sheets, thereby resulting in higher speed operation and production of the machine.

United States Patent Elmer D. Nash 2,730,361 1/19 56 Kerr 271/453,309,078 3/1967 Nash 271/50 X 3,310,169 3/1967 Forrester 271/74 XPrimary Examiner.loseph Wegbreit Assistant Examiner-Bruce H. Stoner, Jr.Attorney-Yount and Tarolli ABSTRACT: The present sheet-feeding apparatushas a plurality of spaced-apart transfer belts through which vacuum isapplied to the underside of a sheet to enable the transfer belts to movethe sheet into a printing press or other machine. A plurality of fingerspress the sheet toward the transfer belts to facilitate the applicationof vacuum to the sheet. In addition, high-velocity jets of air may bedirected along the underside of the sheet, alone or in conjunction withthe fingers, to form areas of low pressure to enable immediate firmgripping of sheets, thereby resulting in higher speed operation andproduction of the machine.

PATENTED SEP1 4 I971 SHEET 1 (IF 5 ATENTEU SEP1 4 |97l SHEET 2 OF 5 m OEPATENTED SEP1 4 I9?! SHEET 3 OF 5 INVENTOR. EZMEE 0. A/A-SH ATTORNEYSmimiusammn 3.5041703 SHEET & 0F 5 INVENTOR. ELMER Q NASH M I ATTORNEYSSHEET-FEEDING APPARATUS This invention relates to a sheet-feedingapparatus having an improved transfer mechanism for transferring thesheet to a sheet-handling machine, such as a rotary printing press,after the sheet has been registered against front stops in the feedingapparatus.

In U.S. Pat. application Ser. No. 727,770 filed May 9, 1968 by C. M.Carey, now U.S. Pat. No. 3,542,360 there is disclosed a sheet-feedingapparatus for use with a rotary sheetfed printing press. In thatapparatus the sheets are advanced successively in underlappedrelationship by a conveyor against front stops, which register theleading edge of the lead sheet, after which the front stops areretracted and the lead sheet is rapidly forwarded by transfer belts to apress cylinder while the conveyor continues to advance the followingsheets. The sheet being transferred is held against the transfer beltsby vacuum which is applied to the underside of the sheet through thetransfer belts. In order to efficiently apply vacuum to the underside ofthe sheet, it is necessary for the sheet to be disposed in engagementwith the transfer belts. Difficulty has heretofore been experienced inapplying vacuum to the underside of the sheet due to space between thesheet and the transfer belts. This difficulty has been particularlyacute when heavy, wavy stock is being fed to the printing press.

The present invention is directed to a transfer mechanism in asheet-feeding apparatus which includes new and improved means for urgingthe sheet into engagement with sheet-feeding means through which vacuumis applied to the underside of the sheet.

Another object of this invention is to provide a new and improvedsheet-feeding apparatus including nozzle means for directing jets of airto urge the sheet into engagement with sheet-feeding means which isoperated contemporaneously therewith to apply vacuum to the underside ofthe sheet and move the sheet toward a machine for working on the sheet.

Another object of this invention is to provide a new and improvedsheet-feeding apparatus including a plurality of fingers which aremovable to and from an operating position in which they press theunderside of a sheet into engagement with sheet-feeding means which isoperated contemporaneously therewith to apply vacuum to the underside ofthe sheet and move the sheet toward a machine for working on the sheet.

Another object of this invention is to provide a new and improvedsheet-feeding apparatus which includes a plurality of transfer belts andsuction means for applying vacuum to the underside of a sheet throughthe transfer belts to enable the sheet to be moved forwardly by thetransfer belts and wherein the application of vacuum to the underside ofthe sheet is facilitated by moving a plurality of fingers from anoperating position in which they are spaced apart from the sheet to anoperating position in which they press the sheet against the beltscontemporaneously with initiation of operation of the suction means.

Another object of this invention is to provide a new and improvedsheet-feeding apparatus in accordance with the nextpreceding object andwherein nozzle means is provided for directing jets of air adjacent tothe underside of the sheet contemporaneously with the aforesaidinitiation of operation of the suction means and movement of the fingersto the operated position.

Another object of this invention is to provide a new and improvedsheet-feeding apparatus which includes a plurality of transfer belts andsuction means for applying vacuum to the underside of a sheet to enableit to be moved forwardly by the transfer belts and wherein theapplication of vacuum to the underside of the sheet is facilitated bydirecting jets of air adjacent to the underside of the sheetcontemporaneously with initiation of operation of the suction means.

Further objects and advantages of this invention will be apparent fromthe following description of a presently preferred embodiment, which isillustrated in the accompanying drawings in which:

FIG. 1 is a top perspective view, with parts broken away for clarity,showing a sheet-feeding apparatus illustrating the present invention;

FIG. 2 is a plan view of the sheet-feeding apparatus of FIG. 1illustrating the relationship between a plurality of transfer beltsthrough which vacuum is applied to the underside of a sheet and fingermembers and nozzles for urging the sheet into engagement with thetransfer belts;

FIG. 3 is an enlarged fragmentary view, partly in side elevation andpartly in section, showing the feeding apparatus of FIG. 1 just beforeit transfers the lead sheet onto a cylinder of a printing press;

FIG. 4 is a view similar to FIG. 3 illustrating the feeding apparatusafter the sheet has been partially transferred onto the press cylinder;

FIG. 5 is a side elevational view of a drive mechanism for moving thefinger members between a plurality of operating positions; and

FIG. 6 is a timing chart showing the timing of certain operations in thesheet-feeding apparatus for FIG. I.

The present invention provides a new and improved mechanism for feedingsheets or sheetlike articles to a machine for working on them, such as aprinting press or cutter and creaser. The feeding mechanism includes aplurality of transfer belts through which vacuum or suction is appliedto the underside of each of the sheets in turn. Once a sheet has beenpressed tightly against the transfer belts by the application of vacuumor suction to the underside of the sheet, the transfer belts are movedforwardly to advance the sheet into the machine. To promote theefficient application of vacuum or suction to the underside of thesheet, finger members are moved to an operating position in which theypress the sheet against the transfer belts contemporaneously withinitiation of the application of vacuum to the underside of the sheet.In addition, air jets can be used separately or in combination with thefingers to urge the sheet against the transfer belts. In the illustratedembodiment of the invention, the air jets are directed along theunderside of the sheet to for in areas of relatively low pressurecontemporaneously with movement of the fingers to the aforesaid operatedposition.

Referring to FIG. 1, the sheet-feeding apparatus in which the presentinvention is embodied includes a conveyor 10 of known design foradvancing sheets or sheetlike articles 12 individually in successionfrom a stack or pile 14. The conveyor includes a plurality of laterallyspaced endless feed tapes 16 which advance the sheets from left to rightin FIG. 1. The sheets 12 are picked up individually from the pile 14 byconventional suckers (not shown) and transferred onto the feed tapes 16beneath overlying pull-in wheels 18. The feed tapes 16 are continuouslydriven across a tape table 20, which is inclined downward to the rightat a slight angle. The sheets 12 are held down against the feed tapes 16by a plurality of rollers 22, which bear down on the sheets withsufficient force to maintain each sheet in frictional engagement withthe feed tapes. Preferably, the sheets 12 are underlapped with thetrailing end of the preceding sheet overlying the leading end of theimmediately following sheet as they are advanced by the conveyor 10.

The feed tapes l6 discharge the successive sheets onto a register plate26 which extends downward to the right from the front ends of the feedtapes at the same angle of inclination as the tape table 20. A pluralityof laterally spaced front stops 30 are provided for engaging andregistering the leading edge of each sheet as it passes over theregister plate 26 and before it is transferred onto a cylinder 32 of aprinting press by the transfer mechanism of the present invention.

Each of these front stops 30 is constituted by a depending lip 36 on thelower end of a respective lever arm 38, which is clamped to a rockershaft 42 extending laterally across the register plate 26 at a locationabove the latter. In the particular embodiment shown the front stops 30and rocker shaft 42 are located above the register plate 26, although itwill be understood that the front stops and rocker shaft could belocated below the register plate if desired.

At one point in each cycle of operation of this sheet-feeding apparatus,shaft 42 is turned counterclockwise, as viewed in FIG. 1, to lift thefront stops 30 up out of the path of movement of the oncoming sheet 12.At another point in each cycle of operation, shaft 42 is turnedclockwise to lower the stops down into the path of the next-succeedingoncoming sheet.

The register plate 26 has openings 46 for receiving the lips 36 of therespective front stops 30 when the respective lever arms 38 are in theirlowered positions, as shown in FIGS. 1 and 3. In these positions, thefront stops are in the path of the front or leading edge 48 of the sheet12a (FIG. 3) which is moving across the register plate 26 from left toright. The front stops 30 are in precise alignment with each otherlaterally across the register plate 26 so that, when engaged by theleading edge of the oncoming sheet, they align this edge in preciseparallelism with the axis of rotation of the press cylinder 32 ontowhich the sheet is to be fed.

-When shaft 42 is turned to raise the front stops 30 (FIG. 4), the frontstops move up out of the path of the sheet 12a which had just beenregistered against these front stops, permitting this sheet to betransferred onto the press cylinder by the transfer mechanism 54 of thepresent invention, to be described.

The sheet-feeding equipment also includes a side register mechanism 56(FIG. 1) of known design. This side register mechanism operatesautomatically to position each sheet at the correct position laterallybefore it is transferred onto the press cylinder 32. This sideregistration of the sheet takes place after its leading edge has beenfront registered by the front stops 30.

A plurality of laterally spaced, movable fingers or members 60, (seeFIGS. 1, 2 and 3), overlie the sheet as it passes over the registerplate 26. These fingers 60 are attached to a rocker shaft 62 extendinglaterally above the tape table 20. The rocker shaft 62 is turned by adrive mechanism 66 (FIGS. 2 and at predetermined times during each cycleof operation to move the fingers 60 between an intermediate position 70(see FIGS. 3, 4, and 5), a lowered position 72, and a raised position74. In the intermediate position 70 the fingers 60 are above theregister plate 26 and transfer mechanism 54 so that they guide the sheet12a into engagement with the front stops 30. After the sheet 12a hasbeen registered relative to the cylinder 32 by leading edge engagementwith the front stops 30, the fingers 60 are moved to the loweredposition 72 by operation of the drive mechanism 66 (FIG. 5). Finally thefingers 60 are moved to the raised position 74 by the drive mechanism 66to enable the sheet to be readily advanced onto the cylinder 32 byoperation of the transfer mechanism 54.

The press cylinder 32 is rotatable at the front end of the registerplate 26 of the sheet-feeding apparatus. This cylinder carries aplurality of gage pins or stop pins 80 (FIGS. 1 and 4) for engagement bythe leading edge of the sheet which is then being transferred onto thecylinder 32. These stop pins 80 are in precise alignment with each otheracross the cylinder 32 along a line extending parallel to the cylindersrotational axis and parallel to the front stops 30.

The press cylinder32 also has a plurality of grippers 82 of known designwhich are all mounted on a cross-shaft 84 carried by the cylinder.

Just before the advancing sheet moves against the front stops 30, itpasses over a plurality of transfer belts 88 in the present transfermechanism. These belts are located at respective laterally spaced,rectangular openings 90 in the register plate 26 (FIG. 2). Each of thetransfer belts 88 has its opposite ends secured to a respectiverotatable drive pulley 92 (FIGS. 3 and 4) which is turned back and forthin opposite directions in timed relationship with the advance of eachsheet against the front stops 30 and with the rotation of the presscylinder 32.

Each transfer belt 88 passes up from one side of the drive pulley 92over a rear guide in the form of an idler roller 94, which is locatednear the rear edge of the respective opening 90 in the register plate26. From this rear idler roller 94 a straight or flat upper rim portion95 of the transfer belt passes through the opening 90 at a levelslightly above the upper surface 96 of the register plate 26. Thetransfer belt 88 then passes around a front guide in the form of anidler roller 98, which is located near the front edge of the opening 90.The transfer belt passes down around this front idler roller 98 and overthe opposite side of the drive pulley 92 to its point of attachment tothe drive pulley.

Between its rear guide roller 94 and the front guide roller 98 the upperrim portion 95 of each transfer belt 88 passes over a respective vacuumtable 102, which is located at the respective opening in the registerplate 26. As shown in FIGS. 3 and 4, this vacuum table has a recess 104at the top across which the respective transfer belt 88 passes. Thisrecess 104 in each vacuum table is connected through a timing valve 106to a source of vacuum. The portion of the transfer belt 88 which passesover this recess 104 has a plurality of openings 108 which enable thevacuum in the recess or chamber 104 to be applied to the underside ofthe sheet 12a which then overlies this portion of the belt.

FIG. 3 shows the position of the drive pulley 92 and the transfer belt88 just after the sheet 12a has moved into registration with the frontstops 30 and side registration of the sheet by the side registrationmechanism 56 has been initiated. The drive pulley 92 is in its extremecounterclockwise position at this time. Shortly before the stop pins 80on the press cylinder 32 have moved up past the front edge of theregister plate 26, jets or high-speed streams of air are directedforwardly along the underside of the sheet 12a by laterally spacednozzles 110 (see FIGS. 2 and 3). The jets of air flow between theunderside of the sheet 12a and upper surface 96 of the register plate 26in areas or passages 114 (FIG. 5) between the straight upper runportions of the transfer belts 88. Since the transfer belts 88 supportthe sheet 12a with only a small clearance between the sheet and surface96 of the register plate 26, the passages 114 are relatively thin orshallow so that the jets of air from the nozzles move through thepassages at a relatively high speed without an increase in the thicknessof the jets of air. The high-speed flow of air through the thin orshallow passages 114 tends to reduce the pressure on the underside ofthe sheet 12a so that it is urged downwardly against the transfer belts88 by the comparatively high pressure on the upper side of the sheet. Inone exemplary embodiment of the invention, the upper surfaces of thebelts 88 were raised above the surface 96 to form passages 114 with athickness of 0.020 of an inch. Of course, passages 1 14 of otherthicknesses can be formed by merely varying the extent to which thebelts 88 project above the surface 96 or by forming recesses in theregister plate 26.

A timing valve 116 is provided for controlling the flow of air to thenozzles 110 and the vacuum tables 102. The timing valve 116 is actuatedby the press drive in timed relationship with the rotation of the presscylinder 32, operation of the finger drive mechanism 66, and theoperation of the valve 106. This timed relationship is such that thefingers 60 are operated from their intermediate position 70 to theirlower position 72 (FIG. 3) after the high-speed streams or jets of airbegin to flow from the nozzles I10. The sheet 12a is then urged firmlydownwardly against the transfer belts 88 by the combined effect of thejets of air and the fingers 60.

Immediately after the fingers 60 are moved to their lower position, thevalve I06 is operated to initiate the application of suction or vacuumto the underside of the sheet 12a. Since the sheet 12a is urged intoengagement with the transfer belts 88 by the combined effect of thefingers 60 and the jets of air from the nozzles 110, there is little ifany space between the underside of the sheet 12a and the upper surfacesof the transfer belts 88. Therefore, vacuum can be quickly applied tothe underside of the sheet 12a through the openings 108 in the transferbelts 88 upon operation of the valve 106. This is important since thesheets 12 are fed in rapid succession to the press cylinder 32 by thetransfer mechanism 54.

Although the fingers 60 and nozzles 110 have been described herein asproviding for a combined downward urging of the sheet 120, it iscontemplated that they could be used separately. In addition, the jetsof air from the nozzles 110 could be left on continuously rather thanbeing interrupted as in the illustrated embodiment of the invention.

After the sheet 120 has been drawn into engagement with the belts 88 bythe application of suction to the underside of the sheet, shaft 62 isturned counterclockwise in FIG. 1 to retract the retaining fingers 60upwardly away from the sheet to the upper position 74. In this upperposition sufficient clearance is provided to enable the sheet to bereadily fed to the press cylinder 32. Next, the front stops 30 areretracted upward away from the leading edge 48 of the sheet 12a, andthen the drive pulley 92 is rapidly turned clockwisefrom the FIG. 3position to the FIG. 4 position by a suitable drive mechanism. Thisforward rotation of the drive pulleys causes the transfer belts 88 tomove from left to right over the guide rollers 94 and 98, carrying withthem the sheet 12a because of the vacuum which continues to be appliedto the underside of the sheet through the openings 108 in the transferbelts.

This forward movement of the transfer belts 88 is at a velocitysubstantially greater than the speed at which the drive tapes 16 areadvancing the following sheets onto the register plate 26 and greaterthan the peripheral velocity of the press cylinder 32. Consequently, thesheet 12a which is advanced by the belts 88 and has its leading edge 48forced into engagement with the stop pins 80 on the rotating presscylinder 32, after which the grippers 82 grip it securely against thepress cylinder in the usual manner. The stop pins 80 register theleading edge 48 of the transferred sheet on the press cylinder. As shownin FIG. 4, the fingers 60 when in the upper or raised position 74 areretracted far enough up away from the sheet 12a to avoid marking thesheet if it bows upwardly after its leading edge first engages the stoppins 80 on the press cylinder 32 and while its training end continues tobe advanced by the belts 88 at a speed greater than the peripheralvelocity of the press cylinder.

After the grippers 82 on the press cylinder 16 have gripped the sheet,the timing valve 106 is operated to disconnect the source of vacuum fromthe recess 104 in the vacuum tables 102. Immediately after the vacuum isdisconnected, the valve 116 connects the vacuum tables 102 to apressurized air source so that the trailing end of the sheet 12a isreleased from the transfer belts 88.

After the trailing edge of this sheet has moved past the front stops 30,the rocker shaft 42 is turned clockwise in FIG. 1 to lower the frontstops 30 into the respective openings 46 in the register plate 26, so asto be positioned for engagement by the leading edge of the next sheet12b (FIG. 3) in the series which is being moved forward continuously bythe feed tapes 16. At the same time, the shaft 62 is pivoted clockwisein FIG. 1 by the drive mechanism 66 to lower the fingers 60 to theintermediate position 70 for guiding the oncoming sheet 12!: on theregister plate 26 without, however, exerting any significant pressure onthis sheet as long as it engages the register plate.

While the oncoming sheet 12b is moved across the register plate 26 andover the transfer belts 88 at the openings 90 in the register plate, airpressure is applied to each vacuum table recess 104 through the valve116 to provide a thin film of air for keeping the underside of the sheetseparated from the corresponding transfer belt 88. At this time, thetransfer belts are being retracted from right to left between the frontguide roller 98 and the rear guide roller 94 by the rotation of thedrive pulleys 92 counterclockwise from the FIG. 3 position. The drivepulleys reach their extreme counterclockwise position, shown in FIG. 3,before the leading edge of the oncoming sheet 12b has reached the frontstops 30. Since the drive mechanism 54 is fully described in theaforementioned application Ser. No. 727,770 filed May 9, 1968 by C. M.Carey, the drive mechanism will not be further described herein.

Referring to FIG. 6, the timing of the different operations of thissheet-feeding apparatus takes place as follows, with reference to therotation of the press cylinder 32, whose 0 position is where the stoppins 80 are aligned with the register plate 26.

The front stops 30 begin to move down at about 200 and they are in theirsheet-registering position at about 240. The fingers 60 also begin tomove down from the upper position 74 at about 200. The fingers 60 reachthe intermediate position 70 at about 240 and remain there to guide thesheet 120 into engagement with the front stops 30. The leading edge 48of the lead sheet 12a reaches the front stops at about 250.

After the front stops 30 reach their sheet-registering position, jets ofair begin to flow out of the nozzles at about 260. The fingers 60 beginto move to the lower position 72 (FIG. 3) from the intermediate position70 at about 310 and reach the lower position at about 319. The sheet 12ais then pressed against the transfer belts 88 under the combined effectof the fingers 60 and the jets of air from the nozzles 110.

The side register device 56 accomplishes the side registration of thesheet during the interval from about 280 to 319 and this registration ismaintained by continuous operation of the side register device untilabout 330.

The application of vacuum to the transfer belts 88 is initiated at about319. Since the sheet is pressed against the transfer belts by thecombined effect of the fingers 60 and jets of air from the nozzles 110,vacuum is readily applied to the underside of the sheet 12a. The fingers60 then begin to move toward the upper position 74 at about 327.Immediately thereafter, the air jets from the nozzles 110 areterminated.

The transfer belts 88 begin their forward stroke at about 330. Thisforward stroke of the transfer belts continues until about 30, but therelease of the vacuum on the transfer belts begins at 10 and iscompleted by 15 to permit the sheet to be readily transferred onto thepress cylinder 32. Air pressure is applied to the vacuum table recesses104 through the valve 116 at the same time that the vacuum is released.

The transfer belts remain in their forward positions from 30 to 40. At40 the transfer belts drive mechanism begins to retract the transferbelts 88. This retraction of the transfer belts takes place from 40 to110, and the vacuum table recesses 104 are subjected to air pressure allthis time. This results in the formation of a thin film of air whichfacilitates movement of the next-succeeding sheet into engagement withthe front stops 30.

The drive mechanism 66 for the fingers 60 includes a cam which ismounted for rotation on a shaft 152 in a timed relationship with thecylinder 32. A pushrod assembly 156 operatively connects the cam 150with the shaft 62 so that upon rotation of the cam 150, shaft 62 isrocked or pivoted to move the fingers 60 between the lower position 72,the upper or raised position 74 and the intermediate position 70.Accordingly, the pushrod assembly 156 includes a follower disk 160 whichis rotatably mounted on a rocker arm 162 which pivots about a shaft 164.Rotation of the cam 150 moves the follower disk 160 from the positionillustrated in solid lines in FIG. 5 in which the fingers 60 are in thelower position 72 to the position illustrated in dashed lines in FIG. 5in which the fingers 60 are moved to the upper position 74.

This motion of the follower disk 160 is transmitted to the fingers 60 bythe pushrod assembly 156 and an actuator lever 168 which is fixedlyconnected to the shaft 62. The assembly 156 includes a pushrod 170 whichis pivotally connected at its lower end to the rocker arm 162. Thepushrod 170 is movable relative to the actuator lever 168 to enablesheets of different thicknesses to be positioned between the transferbelts 88 and the fingers 60. To this end the pushrod 170 is slidableaxially relative to the actuator lever 168 against the influence of abiasing spring 174 which engages a reaction block 176 at one end andpresses at the other end against a slidable connection 178 to theactuator lever 168. Thus, when relatively thin stock is being fed to thecylinder 32, the fingers 60 are pressed downwardly against therelatively thin sheets by the action of the spring 174. Similarly, whenrelatively thick sheets are being fed to the cylinder 32, the fingers 60are movable upwardly against the influence of the spring 174 when thefingers When sheets of different thicknesses are being fed to thecylinder 32, it is often desirable to be able to vary the spacingbetween the fingers 60 and the transfer belt 88 when the fingers are inthe operating position 70, 72 or 74. This is accomplished by rotating anadjusting knob 182 to vary the position of the sliding connection 178relative to the reaction block 176. Of course, the axial movement of theadjusting knob 182 will vary the position or spacing of the fingers 60from the transfer belts when the fingers are in each of the operatingpositions 70, 72 and 74.

During operation of the transfer apparatus 54, the cam 150 is rotated ina counterclockwise direction, as indicated by the arrow 188 in FIG. 5.On rotation of the cam 150 from the position shown in FIG. in which thefingers 60 are in the lower position 72, the follower disk 160 movesalong a ramp 190 through an arcuate distance indicated at 192 to movethe fingers 60 from the lower position 72 to the upper position 74.

' The fingers 60 are maintained in the upper position while the rollerdisk 160 moves along the dwell surface 194 through the relatively largearcuate distance 196. Continued rotation of the cam 150 moves a downramp 200 to a position adjacent to the follower disk 160. Once the cam150 has been rotated through an arcuate distance indicated at 202, thefollower disk engages a dwell portion 204 and the fingers 60 remain inthe intermediate position 70 while the cam is moved through an arcuatedistance indicated at 206 in FIG. 5. The follower disk 160 then movesinto engagement with another down ramp 210 while the cam 150 movesthrough an arcuate distance indicated at 212 in FIG. 5. Finally, thefollower disk again engages a dwell surface 214 and the fingers 60remain in the lower position 72 while the cam 150 is moved through therelatively small arcuate distance indicated at 216 in FIG. 5.

' in view of the foregoing description it can be seen that the sheets 12are registered relative to the cylinder 32 by engagement with the frontstops 30 is guided by the fingers 60 which are maintained in theintermediate position 70 as the sheets move into engagement with thefront stops. This movement of the sheets is promoted by supplying airunder pressure to the recess or chamber 104 in the vacuum table 102.Immediately after the sheet 12a engages the front stops 30, the sheet12a is also urged into engagement with the transfer belts 88 by jets ofair, directed adjacent to the underside of the sheets by nozzles 110.The high-speed movement of the air from the nozzles 110 creates alow-pressure area adjacent to the undersurface of the sheet 12a so thatthe relatively high atmospheric pressure on the upper surface of thesheet presses the sheet downwardly. The sheet is also pressed againstthe transfer belts 88 by movement of the fingers 60 to the lowerposition 72.

Immediately after the fingers 60 have been moved to the lower positionand a flow of air initiated from the nozzles 110, the valve 106 isoperated to connect the recess or chamber 104 in fluid communicationwith a source of suction or vacuum. This vacuum is then applied to theunderside of the sheet 12a through openings 108 in the transfer belts88. The application of vacuum to the underside of the sheet 120 isfacilitated by the fact that the sheet has previously been urged intoengagement with the transfer belts 88 under the influence of the fingers60 and the jets of air from the nozzles 110. While the fingers60 are notmoved to the lower position 72 nor the air jets turned on simultaneouslywith the application of vacuum to the chamber 104, these events occurduring a relatively short time period and are therefore considered tooccur contemporaneously with each other. It should be noted that whilein the preferred embodiment the flow of air form the nozzles 110 isintermittent, it has been found that under certain conditions the airjets can be left on continuously.

Having described my invention, 1 claim:

1. Apparatus for feeding sheetlike articles to a machine for workingthereon, said apparatus comprising means for arresting and registeringleadingedge portions of the sheetlike articles relative to said machine,conveyor means for moving the leading edge portions of each of thesheetlike articles in turn into engagement with said registering meansto effect leading edge registration of the sheetlike articles, beltmeans for gripping and moving the sheetlike articles toward said machineafter registration, first means selectively operable for applying vacuumthrough at least a portion of said belt means to the underside of thesheetlike article overlying said portion of said belt means to therebyurge the underside of the sheetlike article into engagement with saidbelt means, second means for further urging the underside of thesheetlike article into engagement with said belt means, said belt meansincluding a plurality of transfer belts spaced apart from each other ina direction transverse to the direction of movement of the sheetlikearticles, said apparatus further including plate means extending betweensaid transfer belts, said plate means having upper surface areas betweensaid transfer belts and below the upper surfaces of said transfer beltsto thereby form a plurality of relatively wide thin passages betweensaid upper surface areas of said plate means and the underside of thesheetlike article, and said second means including a plurality ofspacedapart nozzle means for directing jets of air through said passagesbetween the upper surfaces of said plate means and the underside of thesheetlike article to thereby tend to form areas of relatively lowpressure between said transfer belts and adjacent to the underside ofthe sheetlike article, and control means for effecting operation of saidfirst means to apply vacuum through said transfer belts to the undersideof the sheetlike article while jets of air are flowing from saidplurality of spaced-apart nozzle means through said wide thin passagesto thereby urge the underside of the sheetlike article into engagementwith said belt means under the combined influence of the vacuum and theareas of low pressure formed by the jets of air.

2. Apparatus as set forth in claim 1 wherein said second means furtherincludes means for applying pressure against the upper side of thesheetlike articles.

3. Apparatus as set forth in claim 2 wherein said means for applyingpressure to the upper side of the sheetlike articles includes aplurality of finger members and said control means includes actuatormeans for moving said finger members between a first position in whichsaid finger members are spaced from the upper side of the sheetlikearticle to enable the sheetlike article to be readily moved into saidmachine once it engages the sheetlike article and a second position inwhich said finger members engage the upper side of the sheetlike articleto press its underside toward said belt means.

4. Apparatus as set forth in claim 1 wherein said control means includesvalve means connected in fluid communication with said nozzle means andwith a source of air under pressure, said valve means being operable todirect air under pressure to said nozzle means during the application ofvacuum to the underside of the sheetlike article by said first means,said valve means also being operable to direct a flow of air to saidfirst means after a sheetlike article has been transferred to saidmachine to thereby facilitate disengagement of the sheetlike articlefrom said belt means and movement of the leading edge ofa-next-succeeding sheetlike article into engagement with saidregistering means.

5. Apparatus for feeding sheetlike articles to a machine for workingthereon, said apparatus comprising means for arresting and registeringleading edge portions of the sheetlike articles relative to saidmachine, conveyor means for moving the leading edge portions of each ofthe sheetlike articles in turn into engagement with said registeringmeans to effect leading edge registration of the sheetlike articles,belt means for gripping and moving the sheetlike article toward saidmachine after registration, first means selectively operable forapplying vacuum through at least a portion of said belt means to theunderside of the sheetlike article overlying said portion of said beltmeans to thereby urge the underside of the sheetlike article intoengagement with said belt means, second means disposed above said beltmeans for applying a downwardly directed pressure against the upper sideof the sheetlike article at a location overlying said belt means topress the underside of the sheetlike article into engagement with saidbelt means,

and control means for operating said first means to apply vacuum to theunderside of the sheet contemporaneously with the application ofpressure against the upper side of the sheetlike article by said secondmeans to thereby urge the underside of the sheetlike article intoengagement with said belt means under the combined influence of saidfirst and second means.

6. Apparatus for feeding sheetlike articles to a machine for workingthereon, said apparatus comprising means for arresting and registeringleading edge portions of the sheetlike articles relative to saidmachine, conveyor means for moving the leading edge portions of each ofthe sheetlike articles in turn into engagement with said registeringmeans to effect leading edge registration of the sheetlike articles,belt means for gripping and moving the sheetlike articles toward saidmachine after registration, first means selectively operable forapplying vacuum through at least a portion of said belt means to theunderside of the sheetlike article overlying said portion of said beltmeans to thereby urge the underside of the sheetlike article intoengagement with said belt means, second means for further urging theunderside of the sheetlike article into engagement with said belt means,said second means including means for applying pressure against theupper side of the sheetlike article to press the sheetlike articledownwardly toward said belt means and a plurality of spaced-apart nozzlemeans for directing jets of air adjacent to the underside of thesheetlike article to thereby form a plurality of areas of relatively lowpressure adjacent to the underside of the sheetlike article, and meansfor operating said second means to press the sheetlike articledownwardly and to form the areas of low pressure adjacent to theunderside of the sheetlike article while said first means applies vacuumto the underside of the sheetlike article to thereby urge the undersideof the sheetlike article into engagement with said belt means under thecombined influence of said first and second means.

7. Apparatus for feeding sheetlike articles to a machine for workingthereon, said apparatus comprising means for registering leading edgeportions of the sheetlike articles relative to said machine, conveyormeans for moving the leading edge portions of each of the sheetlikearticles in turn into engagement with said registering means to effectleading edge registration of the sheetlike articles, infeed means formoving the sheetlike articles toward said machine after registration,said infeed means including selectively operable means for applyingvacuum to the underside of a sheetlike article and moving the sheetlikearticle toward said machine, a plurality of finger members selectivelymovable between a plurality of operating positions, said finger membersbeing operable to a first position in which they are spaced a firstdistance above said infeed means in an orientation to enable said fingermembers to guide the sheetlike articles into engagement with saidregistering means, said finger members being operable to a secondposition in which they engage an upper side of a sheetlike articleoverlying said infeed means and press the sheetlike article intoengagement with said infeed means to facilitate the application ofvacuum to the underside of the sheetlike article by said infeed means,and said finger members being operable to a third position in which theyare spaced from said infeed means by a second distance which is greaterthan said first distance to facilitate transferring of the sheetlikearticle to said machine after the application of vacuum to the undersideof the sheetlike article by said infeed means, and control means forregulating the operation of said infeed means and finger members in sucha manner that said finger members are moved to said second operatingposition contemporaneously with initiation of operation of said infeedmeans to apply vacuum to the underside of the sheetlike article.

8. Apparatus as set forth in claim 7 further including resilient meansfor pressing said finger members against the upper side of the sheetlikearticle when said finger members are in said second operating position.

9. Apparatus as set forth in claim 7 wherein said infeed means includesa plurality of spaced-apart transfer belts, said finger members in saidsecond operating position being located directly opposite said belts.

10. Apparatus as set forth in claim 7 further including nozzle means fordirecting jets of air adjacent to the underside of the sheetlike articlecontemporaneously with the operation of said fingers to their secondoperating position and the initiation of the operation of said infeedmeans to apply vacuum to the sheetlike article.

11. Apparatus as set forth in claim 10 wherein said infeed meansincludes a plurality of spaced-apart transfer belts through which vacuumis applied to the underside of the sheetlike article by said infeedmeans, said nozzle means being positioned to direct the jets of airthrough the spaces between the transfer belts in the direction ofmovement of the sheetlike articles.

12. Apparatus as set forth in claim 7 further including nozzle means fordirecting jets of air adjacent to the underside of the sheetlikearticle, said control means being operable to initiate a flow of airfrom said nozzle means contemporaneously with movement of said fingermembers to said second position and the initiation of the operation ofsaid infeed means to apply vacuum to the underside of the sheetlikearticle.

13. Apparatus as set forth in claim 12 wherein said control means isoperable to effect movement of said finger members to their thirdoperating position and to terminate the flow of air from said nozzlemeans before the application of vacuum to the underside of the sheetlikearticle is terminated to thereby further facilitate movement of thesheetlike article toward said machine by said infeed means.

14. Apparatus for feeding sheetlike articles to a machine for workingthereon, said apparatus comprising means for arresting and registeringleading edge portions of the sheetlike articles relative to saidmachine, conveyor means for moving the leading edge portions of each ofthe sheetlike articles in turn into engagement with said registeringmeans to effect leading edge registration of the sheetlike articles,belt means for gripping and moving the sheetlike articles toward saidmachine after registration, first means selectively operable forapplying vacuum through at least a portion of said belt means to theunderside of the sheetlike article overlying said portion of said beltmeans to thereby urge the underside of the sheetlike article intoengagement with said belt means, second means for further urging theunderside of the sheetlike article into engagement with said belt means,said second means including means for applying pressure against theupper side of the sheetlike articles, and control means for operatingsaid second means contemporaneously with initiation of operation of saidfirst means to thereby urge the underside of the sheetlike article intoengagement with said belt means under the combined influence of saidfirst and second means, said means for applying pressure to the upperside of the sheetlike article includes a plurality of finger members andsaid control means includes actuator means for moving said fingermembers between a plurality of operating positions, said finger membersin a first operating position being spaced a first distance from saidbelt means to enable the sheetlike article to be readily transferred tosaid machine, said finger members in a second operating position beingspaced from said belt means by a second distance which is smaller thansaid first distance to enable said finger members to guide the sheetlikearticle into engagement with said registering means, said finger membersin a third operating position being in engagement with the upper side ofthe sheetlike article to press the sheetlike article into engagementwith said belt means, and wherein a surface is provided slightly belowthe outer surface of the portion of said belt means through which vacuumis applied to the underside to the sheetlike article and said secondmeans further includes means for directing streams of air adjacent tothe underside of the sheetlike article at locations intermediate saidfinger members when said finger members are in said third position, saidairstreams being directed substantially parallel to said surface in thedirection of sheet feed.

15. Apparatus for feeding sheetlike articles to a machine for workingthereon, said apparatus comprising means for arresting and registeringleading edge portions of the sheetlike articles relative to saidmachine, conveyor means for moving the leading edge portions of each ofthe sheetlike articles in turn into engagement with said registeringmeans to effect leading edge registration of the sheetlike articles,belt means for gripping and moving the sheetlike articles toward saidmachine after registration, first means selectively operable forapplying vacuum through at least a portion of said belt means to theunderside of the sheetlike article overlying said portion of said beltmeans to thereby urge the underside of the sheetlike article intoengagement with said belt means, second means for further urging theunderside of the sheetlike article into engagement with said belt means,and control means for operating said second means contemporaneously withinitiation of operation of said first means to thereby urge theunderside of the sheetlike article into engagement with said belt meansunder the combined influence of said first and second means, said secondmeans includes a plurality of finger members and said control meansincludes actuator means for moving said finger members between aplurality of operating positions, said finger members in a firstoperating position being spaced a first distance from said belt means toenable the sheetlike article to be readily transferred to said machine,said finger members in a second operating position being spaced fromsaid belt means by a second distance which is smaller than said firstdistance to enable said finger members to guide the sheetlike articleinto engagement with said registering means, said finger members in athird operating position being in engagement with the upper side of thesheetlike article to press the sheetlike article into engagement withsaid belt means.

1. Apparatus for feeding sheetlike articles to a machine for workingthereon, said apparatus comprising means for arresting and registeringleading edge portions of the sheetlike articles relative to saidmachine, conveyor means for moving the leading edge portions of each ofthe sheetlike articles in turn into engagement with said registeringmeans to effect leading edge registration of the sheetlike articles,belt means For gripping and moving the sheetlike articles toward saidmachine after registration, first means selectively operable forapplying vacuum through at least a portion of said belt means to theunderside of the sheetlike article overlying said portion of said beltmeans to thereby urge the underside of the sheetlike article intoengagement with said belt means, second means for further urging theunderside of the sheetlike article into engagement with said belt means,said belt means including a plurality of transfer belts spaced apartfrom each other in a direction transverse to the direction of movementof the sheetlike articles, said apparatus further including plate meansextending between said transfer belts, said plate means having uppersurface areas between said transfer belts and below the upper surfacesof said transfer belts to thereby form a plurality of relatively widethin passages between said upper surface areas of said plate means andthe underside of the sheetlike article, and said second means includinga plurality of spaced-apart nozzle means for directing jets of airthrough said passages between the upper surfaces of said plate means andthe underside of the sheetlike article to thereby tend to form areas ofrelatively low pressure between said transfer belts and adjacent to theunderside of the sheetlike article, and control means for effectingoperation of said first means to apply vacuum through said transferbelts to the underside of the sheetlike article while jets of air areflowing from said plurality of spaced-apart nozzle means through saidwide thin passages to thereby urge the underside of the sheetlikearticle into engagement with said belt means under the combinedinfluence of the vacuum and the areas of low pressure formed by the jetsof air.
 2. Apparatus as set forth in claim 1 wherein said second meansfurther includes means for applying pressure against the upper side ofthe sheetlike articles.
 3. Apparatus as set forth in claim 2 whereinsaid means for applying pressure to the upper side of the sheetlikearticles includes a plurality of finger members and said control meansincludes actuator means for moving said finger members between a firstposition in which said finger members are spaced from the upper side ofthe sheetlike article to enable the sheetlike article to be readilymoved into said machine once it engages the sheetlike article and asecond position in which said finger members engage the upper side ofthe sheetlike article to press its underside toward said belt means. 4.Apparatus as set forth in claim 1 wherein said control means includesvalve means connected in fluid communication with said nozzle means andwith a source of air under pressure, said valve means being operable todirect air under pressure to said nozzle means during the application ofvacuum to the underside of the sheetlike article by said first means,said valve means also being operable to direct a flow of air to saidfirst means after a sheetlike article has been transferred to saidmachine to thereby facilitate disengagement of the sheetlike articlefrom said belt means and movement of the leading edge of anext-succeeding sheetlike article into engagement with said registeringmeans.
 5. Apparatus for feeding sheetlike articles to a machine forworking thereon, said apparatus comprising means for arresting andregistering leading edge portions of the sheetlike articles relative tosaid machine, conveyor means for moving the leading edge portions ofeach of the sheetlike articles in turn into engagement with saidregistering means to effect leading edge registration of the sheetlikearticles, belt means for gripping and moving the sheetlike articletoward said machine after registration, first means selectively operablefor applying vacuum through at least a portion of said belt means to theunderside of the sheetlike article overlying said portion of said beltmeans to thereby urge the underside of the sheetlike article intoengagement With said belt means, second means disposed above said beltmeans for applying a downwardly directed pressure against the upper sideof the sheetlike article at a location overlying said belt means topress the underside of the sheetlike article into engagement with saidbelt means, and control means for operating said first means to applyvacuum to the underside of the sheet contemporaneously with theapplication of pressure against the upper side of the sheetlike articleby said second means to thereby urge the underside of the sheetlikearticle into engagement with said belt means under the combinedinfluence of said first and second means.
 6. Apparatus for feedingsheetlike articles to a machine for working thereon, said apparatuscomprising means for arresting and registering leading edge portions ofthe sheetlike articles relative to said machine, conveyor means formoving the leading edge portions of each of the sheetlike articles inturn into engagement with said registering means to effect leading edgeregistration of the sheetlike articles, belt means for gripping andmoving the sheetlike articles toward said machine after registration,first means selectively operable for applying vacuum through at least aportion of said belt means to the underside of the sheetlike articleoverlying said portion of said belt means to thereby urge the undersideof the sheetlike article into engagement with said belt means, secondmeans for further urging the underside of the sheetlike article intoengagement with said belt means, said second means including means forapplying pressure against the upper side of the sheetlike article topress the sheetlike article downwardly toward said belt means and aplurality of spaced-apart nozzle means for directing jets of airadjacent to the underside of the sheetlike article to thereby form aplurality of areas of relatively low pressure adjacent to the undersideof the sheetlike article, and means for operating said second means topress the sheetlike article downwardly and to form the areas of lowpressure adjacent to the underside of the sheetlike article while saidfirst means applies vacuum to the underside of the sheetlike article tothereby urge the underside of the sheetlike article into engagement withsaid belt means under the combined influence of said first and secondmeans.
 7. Apparatus for feeding sheetlike articles to a machine forworking thereon, said apparatus comprising means for registering leadingedge portions of the sheetlike articles relative to said machine,conveyor means for moving the leading edge portions of each of thesheetlike articles in turn into engagement with said registering meansto effect leading edge registration of the sheetlike articles, infeedmeans for moving the sheetlike articles toward said machine afterregistration, said infeed means including selectively operable means forapplying vacuum to the underside of a sheetlike article and moving thesheetlike article toward said machine, a plurality of finger membersselectively movable between a plurality of operating positions, saidfinger members being operable to a first position in which they arespaced a first distance above said infeed means in an orientation toenable said finger members to guide the sheetlike articles intoengagement with said registering means, said finger members beingoperable to a second position in which they engage an upper side of asheetlike article overlying said infeed means and press the sheetlikearticle into engagement with said infeed means to facilitate theapplication of vacuum to the underside of the sheetlike article by saidinfeed means, and said finger members being operable to a third positionin which they are spaced from said infeed means by a second distancewhich is greater than said first distance to facilitate transferring ofthe sheetlike article to said machine after the application of vacuum tothe underside of the sheetlike article by said infeed means, and controlmeans for regulating the opEration of said infeed means and fingermembers in such a manner that said finger members are moved to saidsecond operating position contemporaneously with initiation of operationof said infeed means to apply vacuum to the underside of the sheetlikearticle.
 8. Apparatus as set forth in claim 7 further includingresilient means for pressing said finger members against the upper sideof the sheetlike article when said finger members are in said secondoperating position.
 9. Apparatus as set forth in claim 7 wherein saidinfeed means includes a plurality of spaced-apart transfer belts, saidfinger members in said second operating position being located directlyopposite said belts.
 10. Apparatus as set forth in claim 7 furtherincluding nozzle means for directing jets of air adjacent to theunderside of the sheetlike article contemporaneously with the operationof said fingers to their second operating position and the initiation ofthe operation of said infeed means to apply vacuum to the sheetlikearticle.
 11. Apparatus as set forth in claim 10 wherein said infeedmeans includes a plurality of spaced-apart transfer belts through whichvacuum is applied to the underside of the sheetlike article by saidinfeed means, said nozzle means being positioned to direct the jets ofair through the spaces between the transfer belts in the direction ofmovement of the sheetlike articles.
 12. Apparatus as set forth in claim7 further including nozzle means for directing jets of air adjacent tothe underside of the sheetlike article, said control means beingoperable to initiate a flow of air from said nozzle meanscontemporaneously with movement of said finger members to said secondposition and the initiation of the operation of said infeed means toapply vacuum to the underside of the sheetlike article.
 13. Apparatus asset forth in claim 12 wherein said control means is operable to effectmovement of said finger members to their third operating position and toterminate the flow of air from said nozzle means before the applicationof vacuum to the underside of the sheetlike article is terminated tothereby further facilitate movement of the sheetlike article toward saidmachine by said infeed means.
 14. Apparatus for feeding sheetlikearticles to a machine for working thereon, said apparatus comprisingmeans for arresting and registering leading edge portions of thesheetlike articles relative to said machine, conveyor means for movingthe leading edge portions of each of the sheetlike articles in turn intoengagement with said registering means to effect leading edgeregistration of the sheetlike articles, belt means for gripping andmoving the sheetlike articles toward said machine after registration,first means selectively operable for applying vacuum through at least aportion of said belt means to the underside of the sheetlike articleoverlying said portion of said belt means to thereby urge the undersideof the sheetlike article into engagement with said belt means, secondmeans for further urging the underside of the sheetlike article intoengagement with said belt means, said second means including means forapplying pressure against the upper side of the sheetlike articles, andcontrol means for operating said second means contemporaneously withinitiation of operation of said first means to thereby urge theunderside of the sheetlike article into engagement with said belt meansunder the combined influence of said first and second means, said meansfor applying pressure to the upper side of the sheetlike articleincludes a plurality of finger members and said control means includesactuator means for moving said finger members between a plurality ofoperating positions, said finger members in a first operating positionbeing spaced a first distance from said belt means to enable thesheetlike article to be readily transferred to said machine, said fingermembers in a second operating position being spaced from said belt meansby a second distanCe which is smaller than said first distance to enablesaid finger members to guide the sheetlike article into engagement withsaid registering means, said finger members in a third operatingposition being in engagement with the upper side of the sheetlikearticle to press the sheetlike article into engagement with said beltmeans, and wherein a surface is provided slightly below the outersurface of the portion of said belt means through which vacuum isapplied to the underside to the sheetlike article and said second meansfurther includes means for directing streams of air adjacent to theunderside of the sheetlike article at locations intermediate said fingermembers when said finger members are in said third position, saidairstreams being directed substantially parallel to said surface in thedirection of sheet feed.
 15. Apparatus for feeding sheetlike articles toa machine for working thereon, said apparatus comprising means forarresting and registering leading edge portions of the sheetlikearticles relative to said machine, conveyor means for moving the leadingedge portions of each of the sheetlike articles in turn into engagementwith said registering means to effect leading edge registration of thesheetlike articles, belt means for gripping and moving the sheetlikearticles toward said machine after registration, first means selectivelyoperable for applying vacuum through at least a portion of said beltmeans to the underside of the sheetlike article overlying said portionof said belt means to thereby urge the underside of the sheetlikearticle into engagement with said belt means, second means for furtherurging the underside of the sheetlike article into engagement with saidbelt means, and control means for operating said second meanscontemporaneously with initiation of operation of said first means tothereby urge the underside of the sheetlike article into engagement withsaid belt means under the combined influence of said first and secondmeans, said second means includes a plurality of finger members and saidcontrol means includes actuator means for moving said finger membersbetween a plurality of operating positions, said finger members in afirst operating position being spaced a first distance from said beltmeans to enable the sheetlike article to be readily transferred to saidmachine, said finger members in a second operating position being spacedfrom said belt means by a second distance which is smaller than saidfirst distance to enable said finger members to guide the sheetlikearticle into engagement with said registering means, said finger membersin a third operating position being in engagement with the upper side ofthe sheetlike article to press the sheetlike article into engagementwith said belt means.